SURFACE TREATED ADDITIVE FOR PORTLAND CEMENT CONCRETE

摘要

The invention is directed at an additive for incorporation into a cementitious compound comprising Portland cement and water prior to the setting of the compound. The additive is comprised of a surface treated additive wherein the surfaces of the additive are treated with a substance which has a transient hydrophobic effect on the additive, which effect temporarily renders the additive more hydrophobic for a time period following the incorporation of the additive into the compound such that the water comprising the compound is less attracted to the additive during the placement of the compound and is thus available to provide workability to the compound, and such that the additive regains its natural properties following placement of the compound in order to permit the additive to participate with the compound during the curing of the compound. The invention is also directed at a process for preparing the additive and a process for preparing a cementitious compound comprised of the additive.